Print command help on errors

[JonathanRiche]

This is a great lib btw been liking working with it while building my CLI, have one question i'm going to be creating multiple subcommands and have got that working well no issue, however since .target only accepts either subommand or action im not sure of how to have a default command when the user just runs the cli ie blinkx in this case without running the subcommand

ie without the subcommand the user recieves this error ERROR: command 'blinkx' requires subcommand

id like to be able to either surface up the default help or something else by default is.

const app = CliBuilder.App{
        .command = CliBuilder.Command{
            .name = "blinkx",
            .options = &.{
                // Might be better to just have this as a defautl value
                
                .{
                    .long_name = "apikey",
                    .short_alias = 'a',
                    .help = "apikey to display",
                    .envvar = "BLINKX_APIKEY",
                    .required = true,
                    .value_ref = r.mkRef(&model.config.apikey),
                },
            },

            .target = CliBuilder.CommandTarget{
                .subcommands = &.{try content.contentCommand(&r)},

            },
        },
    };

[sam701]

@JonathanRiche this is a good point! 👍 I'll take a look.

[sam701]

@JonathanRiche do you want to take a look on the PR #54 ?

[JonathanRiche]

This is exactly what I was looking for. It looks great 👍

[0x546F6D]

Sorry for hijacking this thread, but I also had in mind to start a discussion about a default command in a list of subcommand.
In addition to the default print error, which is a great addition, what I had in mind was something like a "default" field in the cli.Command that could be set to true, or a special keyword for the name of the default subcommand, like "default_cmd":

.subcommands = try r.allocCommands(&.{
    cli.Command{
        .name = "cmd1",    // or "default_cmd"
        .default = true,
        .description = cli.Description{ 
            .one_line = "command 1 to run by default if no command is passed",
            .detailed =
            \\cmd1 will be run when neither cmd2 nor cmd3 are called
            \\cmd1 could also be run explicitly?
            \\not sure how to deal with the display of cmd1's options though:
            \\- if they were merged with those of the parent cli.Command
            \\-- then those options would be shown with -h, but they would become unavailable if we called cmd2/3
            \\- if they were kept in their own section
            \\-- then the user wouldnt be able to see them with -h
            ,
        },
        .options = try r.allocOptions(&.{..}),
        .target = cli.CommandTarget{..},
    },
    cli.Command{
        .name = "cmd2",
        .description = cli.Description{ .one_line = "command 2 needs to be explicitly called", },
        .options = try r.allocOptions(&.{..}),
        .target = cli.CommandTarget{..},
    },
    cli.Command{
        .name = "cmd3",
        .description = cli.Description{ .one_line = "command 3 needs to be explicitly called", },
        .options = try r.allocOptions(&.{..}),
        .target = cli.CommandTarget{..},
    },
    ...
}),

If no cli.Command in the list of subcommands is set as the default one, then the default print error could be displayed.

Some use-cases:

• an application composed of a back-end (http.zig) and a gui {webui-zig) that would start as a desktop stand-alone application by default, but you could also run just the back-end webserver with the "web" subcommand on one computer, and just the graphical interface with the "gui" subcommand on other computers on the network.
• an application composed of a collection of tools. By default, it would open a graphical interface giving access to all those tools. But with a specific subcommand per tool, you could directly use that particular tool.

I looked into the source code to try to implement it myself but honestly did not go very far until now :)